In laser-light emitting materials illumination systems, a limiting factor to the product performance is the cooling of the light emitting material, for example a phosphor. One of the benefits of putting the phosphor on a rotating wheel is that it distributes the incident energy over a larger area, effectively decreasing the heat density. When a rotating liquid-cooled phosphor wheel is used in high power applications, however, it is necessary to contain a cooling liquid using a rotating seal. Rotating seals have a finite lifespan, which may be less than what is desired for the illumination source or for the projector application. Furthermore, high energy density in a spot of a light emitting material can result in degradation in performance of the material.